1. Field of the Invention
The present invention relates to an apparatus for processing exhaust fluid, and more particularly, to an apparatus for processing exhaust fluid using plasma for removing process by-products such as non-reactive or waste gases generated in a process chamber in the manufacturing process of a semiconductor, a display panel, or a solar cell.
2. Discussion of Related Art
In the manufacturing process of a semiconductor, a display panel, or a solar cell, processes such as ashing, etching, deposition, cleaning, and nitriding are performed in a low-pressure process chamber.
Examples of gases used in the manufacturing process may include 1) a volatile organic compound (e.g., trichloroethylene, 1,1,1-trichloroethane, methanol, or acetaldehyde), 2) acid-based gas, 3) odor-causing material, 4) autoignition gas, and 5) material which causes global warming (e.g., a perfluoro compound), and process by-products such as non-reactive and waste gases which are generated through the manufacturing process.
Since hydrogen fluoride (HF), fluoride, chloride, etc. among the non-reactive and waste gases generated in the manufacturing process corrode metal surfaces while moving in a vacuum pump and a pipe and most of the gases used in the manufacturing process are environmental contaminants, the HF, fluoride, chloride, and gases have to be removed before finally being discharged.
Fine particles and metals generated in the manufacturing processes pass through parts provided in various passages through which a fluid moves such as a connection pipe to be phase-changed into a powder due to cooling or a change in pressure. Such powders are the main cause of the reduced lifespan of the vacuum pump. Also, discharge of the perfluoro compounds into the air is becoming increasingly restricted due to environmental regulations.
Accordingly, existing technology removes the process by-products generated in the low-pressure process chamber by providing a mechanism such as a trap in front of or behind the vacuum pump and performing heating or cooling functions.
Also, since they are disposed behind the vacuum pump and operate in the air using a room pressure plasma method, some plasma processing mechanisms which are currently used have problems because a large amount of energy is used and equipment costs are high. Furthermore, the plasma processing mechanisms have problems since the process by-products accumulate and the vacuum pump has to stop operating when the process by-products generated in the process chamber are introduced into the vacuum chamber.
Meanwhile, a plasma reactor provided in front of the vacuum pump may efficiently decompose the process by-products to prevent energy waste. In particular, the plasma reactor may control the sizes of particles such as the process by-products. Also, when the process by-products are process by-products which are solid in form, the plasma reactor may further improve the mobility of the solid process by-products introduced into the vacuum pump to reduce the accumulation amount in the vacuum pump, thereby extending the lifespan of the vacuum pump.
As such, the plasma reactor that is provided in front of the vacuum pump and generates low-pressure plasma generally uses an inductively coupled plasma method or a radio frequency (RF) driving method.
The plasma reactor using the inductively coupled plasma method that generates plasma by applying voltages to both end portions of an electrode shaped like a coil has a problem in that cost of the equipment is high. The plasma reactor using the RF driving method has a problem in that installation and maintenance costs are high since an RF power supply is very expensive and much power is used for maintenance of plasma.